What are the horizontal structural members used for supporting a ceiling or floor called?

The term that describes horizontal structural members used for supporting a ceiling or floor is joists. Joists are typically installed in parallel rows and support the weight of the ceiling or floor above, distributing loads to the vertical support columns or walls. They are often made from wood, steel, or engineered materials and are essential for ensuring the structural integrity of a building.

In contrast, beams refer to larger horizontal members that support loads across longer spans and are usually used to bear the weight of other structural elements or floors. Trusses are triangular frameworks used to support roofs or bridge structures, providing strength and stability through their design, while plates, often referred to as sole plates or top plates, are horizontal members that connect vertical elements in walls. Understanding the specific functions and designations of these components is crucial for recognizing how buildings are constructed and maintained.